Author Topic: Issues with reflections and shadows using "Ground" material on floor & wall  (Read 12928 times)

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Online DriesV

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Hi,

I'm checking out the Ground meterial in KeyShot 4 to catch shadows and reflections on floor and wall planes simultaneously. I was hoping this would blend my rendered objects much better into a backplate image, but my attempts are not very successful so far... :D

I am attempting to integrate a radiator into an interior backplate. I have aligned the radiator to 2 perpendicular planes that serve as the floor and wall. I have applied the new Ground material to both planes. (ref. images: TEST_rad-in-interior_floor&wall-planes_01 & TEST_rad-in-interior_floor&wall-planes_02)

My issues fall in two main categories:

A. Using environment lighting:
* When I make only the floor plane visible, my image looks OK. (ref. image: TEST_rad-in-interior_EV-lighting_01_floor-visible)
* When I make only the wall plane visible, my image looks OK too. (ref. image: TEST_rad-in-interior_EV-lighting_02_wall-visible)
* When I make both the floor and wall plane visible...my image looks not quite OK. Something strange is going on, due to interaction between floor and wall planes. (ref. image: TEST_rad-in-interior_EV-lighting_03_floor&wall-visible)

B. Using (planar) area lights: (ref. image: TEST_rad-in-interior_area-lights)
(More of a rant actually... ;))
* The floor and wall planes are completely blown out by the area lights. (ref. image: TEST_rad-in-interior_area-lights_01_floor&wall-visible)
The influence of area light brightness on the Ground material is undesirable in this scenario.

I hope someone can help me out! ;)

greetings,
Dries
« Last Edit: February 15, 2013, 07:27:18 am by DriesV »

Online DriesV

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I can make it work by rendering out:
A) the radiator and floor plane on a white background
B) the radiator and wall plane on a white background
C) a render layer with just the radiator (or just render a flat pass to use as an opacity mask later on...)

With compositing in Photoshop I can:
1) Open the backplate
2) Import rendering A and set layer blend mode to 'Screen'
3) Import rendering B and set layer blend mode to 'Multiply'
4) Import the radiator render layer (or mask out the radiator from a copy of A or B)

This is quite a lengthy process. i'd like to render it out in one shot. ;)

Dries

Offline KeyShot

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Can you share your scene with [email protected] so we can take a look at it?

Online DriesV

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Can you share your scene with [email protected] so we can take a look at it?

First thing I'll do on Monday. ;)

In the meantime, has anyone tried this as well?

Dries
« Last Edit: February 15, 2013, 11:30:38 am by DriesV »

guest84672

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Yes - we will take a look.

Online DriesV

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A quick question...

Is the Ground material supposed to work okay on 2 perpendicular planes? I tried it in several scenes and always bumped into the same issues.
GI was on, ground shadows were off.

Dries

Online DriesV

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For anyone to check with KS4...
Sorry, I had to scramble the backplate (commercial stock image). ;)

https://docs.google.com/file/d/0Bw6BI0tv_sN8RWNQWW9fZDgxYnM/edit?usp=sharing

Dries

Online DriesV

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Has anyone tried to use the ground material on perpendicular floor and wall planes?
I'm always getting the unwanted interreflection as previously posted, no matter what settings of the (unlinked) ground material on both planes.

Dries

guest84672

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We looked at it and can't really tell that there is anything wrong with it?

Online DriesV

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Thomas, I was advised to turn specular off for one of the planes. When I do this, I still get the interrefection.
Is it possibel to share a scene where this works for you? Maybe I'm missing some setting.

Dries